In tele-communication or simply communication in short, several societal trends are developing. Firstly, tele-communication is going digital. Be it voice communication in the form of telephony, video communication as in video-calling, radio communication via Satellite, or multi-media communication as in TV (Cable, Satellite or mobile) among others, digital tele-communication systems are becoming commonplace. Secondly, almost all tele-communications systems are based on detailed Standards in order to enable and facilitate communication. Legal and regulatory concerns also need to be addressed and complied to. Thirdly, there is an ever increasing demand for new technologies to provide for anytime, anyplace anywhere communication. Fourthly, there is an ever increasing demand for communication systems to perform better in terms of Quality of Service (QoS). This QoS is generally measured in terms of a number of factors including                voice quality for voice telephony systems        performance of techniques for encoding of information from analog to digital format for voice, images and multi-media data)        security provided to the overall communication        speed and reliability of communication for data and multi-media content using Internet, mobile and TV.        
Finally, technologies such as LCD and Plasma are and displays based on such technologies are increasing in display sizes and resolution detail.
It is expected that many of these trends will continue and grow with the passage of time. Thus, the demands for increased speeds of data communication are expected to grow. Similarly, the demands for the availability and QoS of all types of communication including voice, data, and multi-media content are also expected to grow. It is also reasonable to expect that there will be a demand for much higher resolution displays that are larger in size than the ones that exist today.
For example, in the realm of voice communication, a Vocoder (voice encoder/decoder) that is accepted for the design of a voice communication system may satisfy certain metrics of performance (voice at the receiving end has to intelligible for instance) may not be sufficient in certain other situations. Consider a military situation where some urgent matters are being discussed over the mobile phone. The importance of the conversation is so high that one may seek a better quality and more secure voice from the current communication system. Also it may not be possible to design a new voice communication system dedicated purely for the military.
Similarly, in the realm of data communication, even though the Standards for Communication Channels and digital data representation are well-established, it is often not possible to use the existing Data Channels for the delivery of digital data especially if one wishes to have real-time or near-real time delivery of multi-media digital content/data. This is due to the size of files involved and the speed of data transfer that existing Channels provide. Often, high-resolution multi-media data is further coded into smaller size files with lower resolution to provide for communication over existing Channels, something that may not be acceptable to some users. As displays get bigger, higher resolution multi-media data should be made available at the User Terminals.
Designing new communication networks, whether for voice or data communications, is a massive challenge and to upgrade an existing one may also be an equally massive challenge. This is due to the costs and complexities involved with setting up of the infrastructure for such networks. This is evidenced by the few, if any, attempts to upgrade the land-line (or fixed) telephone or data networks. Even the evolution of mobile network is rather slow. On the other hand, User terminals are easier to build, change, and upgrade. Therefore, while user terminals may be changed frequently, the user terminals still use the existing communications networks to communicate digital information.
“Real Time Data Transmission Over GSM Voice Channel for Secure Voice and Data Applications,” by N N Katugampala, K T A-Naimi, S Villette and A M Kondoz, 13th European Signal Processing Conference EUSIPCO 2005, Turkey, Sep. 4-8, 2005 discusses the use of a Speech Coder which is different than the one used in GSM. Speech is coded at a much lower data rate. Either the coded speech or the data file is then encrypted. A single Voice Channel established using a GSM phone is utilized for transmission of voice and/or data in a secure manner. An Add-on module to the GSM phone is used at the transmitting and receiving ends for carrying out the tasks of speech coding, data encryption etc.
The system, however, suffers from several drawbacks. When used for voice communication, it provides poorer quality voice as the speech is coded using data rates less than the data rates used for voice communication in GSM. When used for data communication, the overall data rate is extremely low making most data intensive applications to either perform at unsatisfactory levels or not perform at all.
Therefore, there exists a need to provide a system and method for voice and data communication to address one or more of the problems mentioned above.